Experiments to determine effects of chlorimuron, clomazone, and imazaquin applied the year before planting corn, cotton, and sorghum were conducted at three locations in Georgia. Corn injury was <20% in 1987 and 1988 and yield was not affected. In 1988, imazaquin applied at a high rate or sequentially the previous year to late-planted soybeans injured corn more than applications to the early-planted soybeans. Cotton was the most sensitive crop to herbicides applied the previous year. However, seed cotton yield was not decreased due to herbicides applied the previous year. Sorghum growth and yield 8 weeks after planting was not affected by soybean herbicide application the previous year. Sicklepod, corn, and wheat bioassays did not detect any of the herbicides in soil samples obtained the season after treatment. Bioassays accurately predicted potential injury in corn and sorghum but not cotton.

Field experiments were conducted at two locations in Georgia to evaluate wild radish control and soft red winter wheat tolerance of herbicides applied February 1 (one- to five-tiller stage) or March 1 (three- to seven-tiller stage). Bromoxynil controlled wild radish with no wheat grain or forage yield reductions in any experiment. Thiameturon controlled wild radish when applied at rates >0.02 kg/ha on March 1. Metribuzin, dimethylamine salt of 2,4-D, and dimethylamine salt of MCPA provided late-season control of wild radish. February 1 treatments of metribuzin reduced wheat stands at Plains. The difference was attributed to environmental conditions, wheat tiller number at application, and possibly to differences in soil fertility at planting. Metribuzin, thiameturon, dimethylamine salt of dicamba, MCPA, and 2,4-D reduced wheat forage yield at Tifton. Dicamba did not control wild radish and reduced grain yield when applied at a rate of 0.3 kg ai/ha on March 1.